msrocky
off to a rocking start
Member since April 2014
Posts: 21
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Post by msrocky on May 3, 2014 22:08:34 GMT -5
Hi All, Does anyone know much about heat treating rocks? I found the following page: FLINT RIDGE FLINT RAW FLINT ON LEFT & HEAT TREATED ON THE RIGHT RETURN TO PAGE TWO These Flint Ridge flakes show the dramatic contrast in color before and after heat treating. The flakes on the left are unaltered as they appear from the Flint Ridge quarries. The more colorful flakes on the right were altered by heating the preforms. Roy uses an electric kiln to heat treat his flint. The process takes from three to four days before the preforms are removed from the oven. He programs the kiln to slowly heat 25 degrees per hour until it reaches a maximum of 500 to 550 degrees. He can control the temperatures close enough to bring out more of the yellows at a slightly lower temperature and more of the reds with a higher temperature. All of these flakes were quarried from Roy Miller's property which is part of the ancient Flint Ridge quarry complex in eastern Ohio. lithiccastinglab.com/gallery-pages/roymillerheatedflakeslarge.htm
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Deleted
Deleted Member
Member since January 1970
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Post by Deleted on May 3, 2014 22:11:31 GMT -5
What's your question ?or am I missing something?
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msrocky
off to a rocking start
Member since April 2014
Posts: 21
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Post by msrocky on May 5, 2014 13:15:30 GMT -5
Well, I was wondering if we could use something other than a kiln. Kilns are expensive.
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Post by kap on May 5, 2014 16:32:15 GMT -5
Come on James chime in here!
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Post by phil on May 5, 2014 18:07:11 GMT -5
You can do it the old fashioned way, but results may vary. Dig a pit 18 inches deep. Put about 12 inches of DRY sand in the bottom. layer your rock on the sand. Only one layer at a time. cover with DRY sand to ground level Build a huge bonfire on top of the sand. Keep it going for at least 8 hours, preferably 12. Totally cover ALL the sand area. when fire out, cover with a tarp to keep any water off, or your rocks could crack or explode. Wait 24 hours for the sand, rocks to cool down. Dig and see if it worked.
method #2. use one of those electric roasters that goes to 550F instead of a kiln. I forget the steps tho, you should be able to find them online. Gotta be careful tho, the heating cols line only certain areas of the pan, creating spots too hot and too cool.
hope that helped, that's all I know.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,709
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Post by Fossilman on May 6, 2014 10:17:17 GMT -5
James has a simple recipe to use....I'm going to start using a turkey roaster my wife is giving up(for a new one)....They cost about $40.00 at any retail store..... I have his recipe here somewhere....I'll look..
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Fossilman
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Member since January 2009
Posts: 20,709
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Post by Fossilman on May 6, 2014 10:21:47 GMT -5
Ok found it....
Heat treat rock 50 degrees - 100 degrees per hour...Up to 450 degrees - Hold for an hour... Then ramp temp. down by same 50 degrees - 100 degrees per hour to cool........
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msrocky
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Member since April 2014
Posts: 21
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Post by msrocky on May 9, 2014 16:25:22 GMT -5
Ok found it.... Heat treat rock 50 degrees - 100 degrees per hour...Up to 450 degrees - Hold for an hour... Then ramp temp. down by same 50 degrees - 100 degrees per hour to cool........ Do you start at 50 degrees? I could most of this in my oven in my kitchen. lol
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msrocky
off to a rocking start
Member since April 2014
Posts: 21
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Post by msrocky on May 9, 2014 16:26:12 GMT -5
I guess you meant increase the heat by 50 degrees every half hour?
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stephent
starting to spend too much on rocks
Member since March 2014
Posts: 213
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Post by stephent on May 9, 2014 16:34:53 GMT -5
yes...going up slowly on temp keeps the stones/rocks from exploding if they have water inside (it will slowly boil off and out) ...or thermal cracking (maybe).. Going (ramping) slowly down keeps them from thermal cracking...(again..probably).
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msrocky
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Member since April 2014
Posts: 21
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Post by msrocky on May 10, 2014 11:40:14 GMT -5
I've got a batch in the oven right now. We'll see what happens! lol
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dtcmor
freely admits to licking rocks
Back to lickin' rocks again!
Member since May 2006
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Post by dtcmor on May 10, 2014 21:52:20 GMT -5
Here is a link to a site for heat treating. It has some "recipies" for different stone as not all rocks cook the same way or at the same temps. I use the turkey roaster for flint ridge material with great results. To get the higher temps above 450deg. I take the inner pan out - this will give you between 500-550deg. Hope this helps. orerockon.com/Heat_treating.htmDave
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Fossilman
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Post by Fossilman on May 12, 2014 23:12:53 GMT -5
How much sand do you use in the roaster? I'm going to cook Montana agate too....
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dtcmor
freely admits to licking rocks
Back to lickin' rocks again!
Member since May 2006
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Post by dtcmor on May 13, 2014 2:05:35 GMT -5
I usually have the roaster filled just about to the top. I put about an inch of sand on the bottom and then a layer of stone. Make sure the pieces dont touch each other (I leave about a half inch between pieces all the way around),and then fill that layer in with more sand covering that layer about an inch over. I alternate layers like that, sand/stone/sand/stone, until the roaster is full. One note also, the sand should be dry before starting just like the rock. I use regular play sand and put it out in the sun for a couple of days on a tarp. I do about 10 roaster fulls before I change the sand out - the heat tends to break it down after a while and it will turn powdery and thin.
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Fossilman
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Member since January 2009
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Post by Fossilman on May 13, 2014 19:37:02 GMT -5
AWESOME!!!!!
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